The main components of solar systems are modules (or panels) and inverters, if you are not sure what these are you should first check out the article How Solar Works. We have three main criteria when deciding on our favourite solar product, they are; quality, which encompasses performance and reliability; service, which includes warranty and company size, and; value, which is a combination of quality, service and cost. It’s easy to know what to consider when buying solar but difficult to find out if a certain manufacturer offers quality, service and value. You can check out how our Solar Specialists rate different manufacturers at our inverter and solar panel summary pages, or my articles on our favourite modules and inverters. Our Specialists have rated inverter manufacturers for Quality and Service out of 10 and panels for Quality out of 10. 1 being very poor and 10 being excellent. The summary tables have other useful information that can help evaluate the quality, service and value that a particular manufacturer offers.

Quality

Let me begin with the most important consideration; quality. It is very important that your solar system is reliable. Whether you have bought your solar system for environmental or economic reasons you want it to run hassle free for the life of the system, which should be over 20 years. There is nothing more frustrating than having your system break down and it taking months to get fixed. Or even worse, if your system breaks down and you don’t even notice for months. As discussed elsewhere, the inverter is a much more complicated piece of equipment than the module. Therefore it is more likely that it will break down, so you should ensure that the inverter manufacturer knows what they are doing. Whilst it’s easier to make reliable modules than inverters, it’s still very important that the modules are high quality, because if one breaks down it could have a serious effect on system performance. Also, module technology improves rapidly so if you have a problem with a panel in five years you might not be able to get a replacement of the same panel, which can cause serious problems.

Efficiency can be an indicator of quality, though you will notice on the solar module and inverter info tables, most comparable modules and inverters have similar efficiencies. However, there are constant improvements with efficiencies in solar modules and you can get modules that are over 30% more efficient than others on the market today. Which means, although you will pay considerably more for the same power output for these modules, you get more power generation from the same roof space, which is useful if you have a small roof.

Another consideration is manufacturing location, which I don’t like to focus on too much, because you can get great quality products made anywhere. Although, I will say this, not all Chinese made solar products are well made, but most German made products are. Just remember though, many great companies, even Apple, manufacture in China because it can be much more cost effective.

Service

The second line of defence after quality, is service, which includes warranty. Even the highest quality products occasionally have faults, which you can’t avoid, but you can try and ensure you buy from a company that handles warranty and service problems well. Solar warranties can be a little tricky to understand, I will explain them in a separate blog on warranties. Most solar manufacturers offer similar warranties, however, it’s not much use having a warranty if it’s impossible to find whoever is responsible for it, or if it takes them ages to address a fault.

The size of the manufacturing company can be a good indication of whether they will be around in years to come. We have tabled if manufacturers are publicly listed on a stock exchange, and also whether they have a local service centre at our solar inverter and module pages.

Value

My final consideration is value. Value is a combination of quality and cost, and is very important to most people, who either want the best payback period, or want to have the biggest impact on greenhouse gas emissions. Value allows us to produce the most solar energy for the cheapest price. It’s easy to find high quality products at a high price, but there are very good products out there for great prices as well.